Electroplating apparatus

ABSTRACT

An electroplating apparatus, in accordance with the present invention, includes a plurality of chambers. A first chamber includes an anode therein. The first chamber has an opening for delivering an electrolytic solution containing metal ions onto a surface to be electroplated. The surface to be electroplated is preferably a cathode. A second chamber is formed adjacent to the first chamber and has a second opening in proximity of the first opening for removing electrolytic solution containing metal ions from the surface to be electroplated. The plurality of chambers are adapted for movement in a first direction along the surface to be electroplated.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electroplating devices, and moreparticularly to a method for fabricating a thin film transistor arrayfor a liquid crystal display with an electroplated gate or data metal.

2. Description of the Related Art

Displays, such as, liquid crystal displays, have found a wide range ofuses in modern electronic equipment. With the improvement of viewingquality and the reduction of viewing angle limitations, liquid crystaldisplays have become more appealing for a plurality of new applicationsand well as more desirable for old applications. In many instances,liquid crystal displays are replacing cathode ray tube (CRT) displays.For example, liquid crystal displays are now being employed for computermonitors.

Liquid crystal displays, in many applications, provide desirablefeatures, such as light weight, low profile and low power, to name afew. Due to increased usage of liquid crystal technology, there is alarge driving force to reduce the costs of such displays. One way toreduce the costs of liquid crystal displays is to reduce the number ofprocessing steps needed to fabricate these devices. For example, manyliquid crystal display thin film transistor TFT arrays are fabricated inprocesses which include a plurality of masking steps. It would beadvantageous to reduce the number of masking, deposition, and etchingsteps used to build these TFT arrays. The industry is currently movingto five mask processes, but it is desirable to reduce the number furtherto four mask steps.

Therefore, a need exists for a method for fabricating a TFT array inless than five masking steps. A further need exists for providing adisplay device produced by this method which includes an electroplatedgate or data metal, since metal deposition by electroplating is lowercost then conventionally employed sputtering processes.

SUMMARY OF THE INVENTION

An electroplating apparatus, in accordance with the present invention,includes a plurality of chambers. A first chamber includes an anodetherein. The first chamber has an opening for delivering an electrolyticsolution containing metal ions onto a surface to be electroplated. Thesurface to be electroplated is preferably a cathode. A second chamber isformed adjacent to the first chamber and has a second opening inproximity of the first opening for removing electrolytic solutioncontaining metal ions from the surface to be electroplated. Theplurality of chambers are adapted for movement in a first directionalong the surface to be electroplated.

In alternate embodiments, the plurality of chambers may include a rinsechamber including a supply of water for rinsing the surface, and/or apretreatment chamber which leads the first chamber for pretreating andcleaning the surface to be electroplated. The surface to beelectroplated preferably includes conductive lines, although otherfeatures may be plated as well. The conductive lines may extendlongitudinally along the first direction. The conductive linespreferably connect to a common node. The apparatus may include aplurality of first chambers and a plurality of second chambers. Theanode may include a consumable metal anode. The anode may include aninert metal and the electrolyte solution may include ions of a metal tobe deposited. The first chamber may be surrounded by the second chamber,for example in a pipe within a pipe arrangement. The pipes may be of anyshape, for example circular in cross-section, or rectangular incross-section or combinations thereof. The second chamber may include aplurality of chamber which surround the first chamber.

A method for forming an electroplated metal on conductive layers, inaccordance with the present invention, includes the steps of providing asubstrate having elongated conductive structures formed thereon,providing an electroplating apparatus including a plurality of chambers,a first chamber including an anode therein, the first chamber includinga first opening for delivering an electrolytic solution containing metalions onto the conductive structures to be electroplated, the conductivestructures being a cathode, and a second chamber formed adjacent to thefirst chamber and having a second opening in proximity of the firstopening for removing electrolytic solution containing metal ions fromthe conductive structures to be electroplated and moving the pluralityof chambers in a first direction along the conductive structures to beelectroplated to electroplate the metal onto the conductive structures.

In other methods, the plurality of chambers may include a rinse chamber,and the method may further include the step of rinsing an electroplatedsurface of the conductive structures. The plurality of chambers mayinclude a pretreatment chamber which leads the first chamber, and themethod may further include the steps of pretreating and cleaning theconductive structures to be electroplated. The conductive structures mayinclude gate of data lines for active devices. The conductive structuresmay extend longitudinally along the first direction. The conductivestructures may connect to a common node during electroplating. Theelectroplating apparatus may include a plurality of first chambers and aplurality of second chambers, and the method may further include thestep of incrementally electroplating the conductive structures with eachof the plurality of first chambers.

In still other methods, the anode may include a consumable metal anodeor the anode may include an inert metal and the electrolyte solution mayinclude ions of a metal to be deposited. The step of providing anelectroplating apparatus may include the step of providing the apparatusin which the first chamber is surrounded by the second chamber.

A method for fabricating an active array for a liquid crystal displaydevice, in accordance with the present invention, includes the steps offorming addressing lines for the active array, providing anelectroplating apparatus including a plurality of chambers, a firstchamber including an anode therein, the first chamber including a firstopening for delivering an electrolytic solution containing metal ionsonto the addressing lines to be electroplated, the addressing linesbeing a cathode, and a second chamber formed adjacent to the firstchamber and having a second opening in proximity of the first openingfor removing electrolytic solution containing metal ions from theaddressing lines to be electroplated, and moving the plurality ofchambers in a first direction along the addressing lines to beelectroplated to electroplate the metal onto the addressing lines.

The addressing lines may include indium tin oxide or indium zinc oxide.The addressing lines may extend longitudinally along the firstdirection. The addressing lines may connect to a common node duringelectroplating The methods may further include the steps of formingaccess devices for accessing pixel electrodes through the addressinglines and forming data lines for addressing the pixel electrodes. Theaddressing lines may be included in a top gate structure or a bottomgate structure. The method is preferably performed in only four maskingsteps. The method may further include the step of forming access devicesfor accessing pixel electrodes through gate lines, where the addressinglines are for addressing the pixel electrodes. The active array mayinclude conductive structures isolated from the cathode such thatelectroplating is prevented on the conductive structures. The conductivestructures may include pixel electrodes.

These and other objects, features and advantages of the presentinvention will become apparent from the following detailed descriptionof illustrative embodiments thereof, which is to be read in connectionwith the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

The invention will be described in detail in the following descriptionof preferred embodiments with reference to the following figureswherein:

FIG. 1A is a top view of a single pixel cell having an electroplatedgate metal in accordance with the present invention;

FIG. 1B is a cross-sectional view of the pixel cell taken at sectionline 1B—1B of FIG. 1A in accordance with the present invention;

FIG. 2 is a cross-sectional view of an electroplating apparatus inaccordance with the present invention;

FIG. 3 is a top view of the electroplating apparatus of FIG. 2 forplating gate lines in an array of pixels in accordance with the presentinvention;

FIG. 4 is a cross-sectional view of another electroplating apparatus inaccordance with the present invention showing multiple metal layersbeing electroplated in a single pass;

FIG. 5 is a cross-sectional view of an electroplating apparatus showingsupply and return lines in accordance with the present invention;

FIG. 6A is a top view of the single pixel cell of FIG. 1A having an atri-layer insulator applied and patterned in accordance with the presentinvention;

FIG. 6B is a cross-sectional view of the pixel cell taken at sectionline 6B—6B of FIG. 6A in accordance with the present invention;

FIG. 7A is a top view of the single pixel cell of FIG. 6A having an asemiconductor layer applied and patterned in accordance with the presentinvention;

FIG. 7B is a cross-sectional view of the pixel cell taken at sectionline 7B—7B of FIG. 7A in accordance with the present invention;

FIG. 8A is a top view of the single pixel cell of FIG. 7A having an adata metal applied and patterned in accordance with the presentinvention;

FIG. 8B is a cross-sectional view of the pixel cell taken at sectionline 8B—8B of FIG. 8A in accordance with the present invention;

FIG. 9A is a top view of a single pixel cell having a light shieldformed and patterned in accordance with the present invention;

FIG. 9B is a cross-sectional view of the pixel cell taken at sectionline 9B—9B of FIG. 9A after being overcoated with an insulator inaccordance with the present invention;

FIG. 10A is a top view of the single pixel cell of FIG. 9A having a datametal formed and patterned in accordance with the present invention;

FIG. 10B is a cross-sectional view of the pixel cell taken at sectionline 10B—10B of FIG. 10A in accordance with the present invention;

FIG. 11A is a top view of the single pixel cell of FIG. 10A having asemiconductor material and an insulation layer formed and patterned inaccordance with the present invention;

FIG. 11B is a cross-sectional view of the pixel cell taken at sectionline 11B—11B of FIG. 11A in accordance with the present invention;

FIG. 12A is a top view of the single pixel cell of FIG. 11A having atransparent conductor and an electroplated metal formed and patterned inaccordance with the present invention;

FIG. 12B is a cross-sectional view of the pixel cell taken at sectionline 12B—12B of FIG. 12A in accordance with the present invention;

FIG. 13 is a cross-sectional view of an annular nozzle having thecapability of scanning in two directions to perform electroplating inaccordance with the present invention; and

FIG. 14 is a top view of the nozzle of FIG. 13 in accordance with thepresent invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention relates to electroplating devices, and moreparticularly to an improved fabrication method which produces a thinfilm transistor array for liquid crystal display devices in four maskingsteps. The present invention also provides a method and tool for formingan electroplated metal layer for a gate used for the thin filmtransistors in the array.

A method for a four mask thin film transistor (TFT) array process withan electroplated gate metal will now be described in greater detail. Thepresent invention will be described in terms of a liquid crystalstructure which may include active matrix displays. Other displaystructures, as well as, other device structures may also find utilityin/with the present invention.

Referring now in detail to the figures in which like numerals representthe same or similar elements and initially to FIGS. 1A and 1B, atransparent conductive layer 10 is formed on a substrate 12. Transparentconductive layer 10 may include materials such as, for example, indiumtin oxide (ITO), indium zinc oxide (IZO) or the like. Substrate 12 mayinclude glass, quartz, a polymer or other transparent substratematerial. Transparent conductive layer 10 is deposited and patterned toform gate lines 14 and pixel electrodes 16 for a liquid crystal display8.

A metal layer 18 is formed on gate lines 14. Metal layer 18 ispreferably formed by electroplating. Metal layer 18 is employed toselectively coat gate line 14 with a metal, such as, for example, Ni,Au, Co, Cu, Ag, alloys of these metals or other metals or metal alloysto reduce gate metal resistance. Advantageously, gate lines 14 arecontinuous across substrate or plate 12, and all gate lines 14 can beaccessed along one edge of substrate 12 and electrically contacted foran electroplating process as will be described below. A contact (notshown) can later be cut, for example, during dicing of substrate 12.Pixel electrodes 16 are each electrically isolated. Since no potentialis applied to pixel electrodes 16 during electroplating, pixelelectrodes 16 will not have any metal electroplated thereon.

A novel plating technique is preferably employed to deposit a uniformlayer of metal along gate lines 14 due to the high resistance (of gatelines 14). Since gate lines 14 are electrically conducting, it ispossible to make an electrical connection to gate line 14, and toelectroplate copper, nickel, cobalt, gold, silver, alloys of thesemetals or any other metal or metal alloys thereon.

One difficulty using conventional techniques is that all commonly usedplating solutions are highly electrically conducting and the currentflowing from an anode through the body of the solution to thetransparent conductive material of gate lines 14 (cathode) will bediverted to an area near or closer to which the electrical contact ismade. The plating will start at this point, but because the transparentconductive layer 10 (such as an ITO layer or even a thin metal pattern)is not sufficiently conducting, the depositing metal front will bemoving only very slowly along the length of the pre-patterned gate lines14. The thickness uniformity even on top of a pre-patterned gate lines14 would be unacceptable. Due to higher conductivity, the metaldeposited near the cathode contact point will continue thickening whilethe plating along the length of the gate line 14 will proceed extremelyslowly. As a result, ITO conductors even on a small plate of glass willhave an extremely non-uniform thickness profile. So far there have beenno literature reports which would show that a uniform thickness of metalcan be obtained by electroplating on very thin pre-patterned metalconductors or on ITO.

When it is desired to produce metal patterns by electroplating inaccordance with the prior art, a conventional dielectric substrate ismetallized with a thin continuous highly conductive film, the substrateis then coated with a photo-resist. After exposure and development, thesubstrate is electroplated through a resist mask, the resist mask isremoved, and the thin metal seed layer is removed by chemical etching,sputter etching, reactive ion etching (RIE), or ion milling.

Referring to FIG. 2, to overcome this problem of the prior art and tocut back on the number of process steps, a closed anode compartment orchamber 202 on an electroplating apparatus or composite cell 220 isemployed with a narrow slit or nozzle 204 through which a fresh platingsolution and electrical current are supplied. An anode 203 may be aninert metal, such as, for example, platinum or titanium or a consumablemetal, such as, for example, Cu, Ni, Au, Co, Ag and/or alloys of thesemetals that supplies metal in solution to be electro-deposited on asurface to form metal layer 212. If an inert anode is employed, themetal (e.g., Cu, Ni, Au, Co, Ag, alloys of these metals, etc.) issupplied as ions in the electrolyte solution.

It is to be understood that consumable anodes need to be continuouslyfed to maintain the anode to cathode distance. When used up, theconsumable anodes need to be replaced with new anodes. For inert anode,appropriate measures should be taken to account for the generation ofoxygen gas (O₂) during plating and prevent the generation of oxygenbubbles from interfering with electrolyte flow and the metal ionreduction process at the cathode. In one embodiment, linear andvolumetric solution flow past the anode is very fast so that oxygen hasno time to form and very little dilution of the plating solution takesplace. In another embodiment, the rate of oxygen generation ismaintained at a low enough rate such that generated oxygen is soluble inthe electrolyte solution. In yet another embodiment, anode area is largeso that oxygen gas bubbles do not form on the anode.

It is further to be understood that slit or nozzle 204 may represent aslit-type tool or an annular nozzle. In one example, the slit-type toolmay include a plurality of slits (e.g., square shaped channels) where afirst slit include the anode and an adjacent slit provide an electrolytereturn path. Other slit-type designs are also contemplated. One exampleof a nozzle type tool may include an annular structure with an innertube including the anode and an outer annulus chamber(s) for return flow(or vice versa).

In one embodiment, a separate anode may be eliminated by making chamberwalls 211 from an anodic material (inert or consumable). Alternately,anode(s) may be embedded in chamber walls 211.

A separation S between an opening 206 of slit 204 and conductivematerial 208, for example, transparent conductive layer 10, which mayinclude ITO, is very small. For example, the separation S may be assmall as or smaller than one millimeter. This separation S depends onlayer 10 conductivity pattern density, solution conductivity and patternresolution desire.

Referring to FIGS. 2 and 3, anode compartment 202 is scanned along thelength of conductive material 208, for example, gate lines (or datalines) 14, starting from a point of electrical contact 210. Scanningrate depends on factors such as current density and mass transport rate.These factors may be controlled with parameters, such as, current flowand electrolyte flow/composition to yield desired thicknesses, tapers,etc. In the arrangements described in the invention, as soon as thedesired thickness of metal 212 (e.g., copper, nickel, cobalt, gold,silver and/or alloys of these metals, etc.) is electroplated, a supplyof the plating solution and of the electrical current is cut off to theplated section of gate line 14 by the motion of the composite cell 220.FIG. 2 shows a possible solution supply nozzle/water rinse arrangement.This is one of the many possible arrangements. It is also possible toenvision a more complex arrangement including several such nozzlesfollowing each other and either thickening the electro-deposited metalor over-coating it with a protective layer of another metal or similarmaterials. If the conducting lines are plated using metals, such as, Nior Co, no cladding may be needed. If the conducting lines are platedwith metals, such as, Cu, Au, Ag, (or alloys thereof), the metals mayneed to be clad (covered) with a either a barrier, such as, a metal oran adhesion metal layer (e.g., Ni on top of Au). This barrier may beplated using, for example, a second pass (or a second scanner of thesame composite cell) of the electroplating apparatus of the presentinvention. The barrier may also be deposited using electroless (dip)techniques. An electroplated barrier may include, for example, Ni, Co,NiCo or Cr. An electrolessly deposited barrier may include, for example,Ni, Co or alloys thereof, such as NiP, CoP, CoWP, CoSnP, etc.

As shown in FIG. 2, one slit (nozzle) 204 is used to provide the platingsolution, while an adjacent slit 214 is used to quickly withdraw thefluid. The plating solution and hence the electrical current makecontact only over a very short length of gate lines. This permits theadvance of a plating metal front 216 while making a low resistivityelectrical contact through the already metal-plated conductive line 208.The thickness of the deposit will be determined by the concentration ofthe plating solution, the separation between the two slits (204 and 214)(solution entry and solution exit), the local current density and therate at which anode compartment 202 is moved relative to the gate line14. The direction of motion in the illustrative example, shown in FIGS.2 and 3, is indicated by arrow “A”.

To make sure that salt residue does not get left behind to start acorrosion process, plating nozzle or slit 204 and suction nozzle or slit214 are followed by a water rinse nozzle 216 and an additionalsuction-drying nozzle 218 (nozzles 216 and 218 may be reversed). Apretreatment/cleaning chamber 230 may be provided for preparing thesurface to be electroplated. Cleaning/pretreatment may include a rinsewith water or water with detergent or a soluble organic solvent such as,ethanol, or acetone. Chamber 230 may include a supply slot and a suctionslot to deliver and remove cleaning/pretreatment materials.

Referring again to FIG. 3, a “plating/drying/rinsing/drying” combinationcell 220 is scanned over gate lines 14 from a first edge 222 to anopposite edge 224 of an active matrix array 221 on substrate 12. Array221 includes pixel electrodes 16. The scanning is started from end 222of substrate 12 which electrically connects to gate lines 14 or otherconductive structures.

In the illustrative embodiment shown in FIG. 3, a shorting bus 226 ispatterned along with gate lines 14 and functions as a connection pointand a cathode for electroplating gate lines 14. Advantageously, gatelines 14 are continuous across substrate or plate 12, and all gate lines14 can be accessed along edge 222 of substrate 12 and electricallycontacted for the electroplating process by employing shorting bus 226.Shorting bus 226 can later be cut off, for example, during dicing ofsubstrate 12 or etched away. After beginning the scanning of cell 220 atthe contact point 226, scanning continues to the unconnected end 224along the length of gate lines 14 (in the direction of arrow “A”).

For best uniformity of deposited metal thickness, it is preferred thatslit 204, supplying the solution, always moves at about a right angle tothe length of gate lines 14. One skilled in the art would understandthat if a thickness variation were desired along the length of gatelines 14, it would be possible to achieve this by modulating thecurrent, scan speed, rate of supply of electrical current or solutionconcentration to locally thin down or thicken the lines. It is furthernoted that pixel electrodes 16 are electrically isolated from gate lines14, shorting bus (cathode) 226 and each other. Therefore, pixelselectrodes 16 are not affected by the electroplating process.

Another advantage of forced-electrolyte plating, as shown in FIGS. 2 and3, in accordance with the present invention, of transparent electrodematerials (IZO or ITO) is that the profile of the deposited metal filmmay be controlled by the design and operation of the plating assembly(e.g., cell 220).

Since the plating assembly or cell 220 (FIG. 2) may be operated ineither a mass transfer-limited regime or a kinetic-potential(cathode-anode) limited regime, a taper 31 (FIG. 1B) may be controlledby altering the geometry of the plating nozzle 204 or the conditions ofoperation such as scanning rate, flow rate, pressure, electrolytecomposition, and temperature. To further control taper 31 (FIG. 1B) andensure uniform thickness of the electroplated layers, the finishedelectroplated materials of taper 31 (FIG. 1B) may be plated/etched usingconventional techniques (e.g., submerged in liquid electrolyte).Electrical connections for further plating of metal 212 may be made inthe same fashion as used in the forced-electrolyte technique describedfor FIG. 3. The control of potential and electrolyte composition may beoptimized to achieve uniform metal films with tapered edges 31.

The present invention has been described illustratively for a situationin which ions are supplied only through one slotted assembly (e.g., slit204), it is, however, contemplated that the plating apparatus mayinclude a plurality of slotted assemblies following each other. Eachslotted assembly may build up slightly more thickness of the platedmetal line or may deposit a barrier protective layer, for example, Co,Cr or Ni.

Referring to FIG. 4, an electroplating tool 302 may be employed in whicha plating solution 304 and an anode 306 are scanned over conductivelines or conductive patterns 309, for example, gate lines 14. In oneembodiment, anode 306 may include a hollow conductive carbon orinsoluble (inert) metal rod wrapped with a lintless cloth or a porouspolymer 312. Plating solution 304 may be supplied through a cavity 314inside of anode rod 306 and lintless cloth or porous polymer 312 mayslide over in contact with the patterned conductive layer 309 (which arepreferably connected in a cathode mode) or gapped to provide a distanceS. With this method the viscosity of the plating solution may need to beincreased to achieve the desired thickness uniformity. FIG. 4 showssuction chambers 315 for removing solution 304 after electroplatinglayers 316 and 318. FIG. 4 shows apparatus 302 with two supply slotsthrough cavities 314 of anodes 308 and two return slots 315. Otherembodiments may include one supply and one return slot or multiplesupply and return slots. In still other embodiments rinsing andpretreating chambers may be included.

Referring to FIG. 5, a schematic diagram of one embodiment of anelectroplating apparatus of the present invention, e.g., apparatus 220or 302, is illustratively shown. Walls 340 form chambers 342 throughwhich fluids flow for electroplating, rinsing and pretreating conductivestructures. Supply line 350 provides pretreatment/cleaning fluid whichis subsequently removed by return line 352. Supply lines 354 provideelectrolyte solution with metal ions from an anode(not shown) which issubsequently removed by return lines 356. Similarly, supply and returnlines 358 and 360, respectively supply and return rinsing water. Supplylines 350, 354, and 358 may be appropriately pressurized to provide theability to adjust flow rates; while suction may be applied to returnlines 352, 356 and 358. One skilled in the art would understand how toadjust the area, pressure and flow rates of outlets and inlets of supplyand return lines and slots (see, e.g., FIG. 2) to achieve a desiredflow.

Although a batch process has been illustratively described, the presentinvention is amenable to a continuous line operation. Such continuousline operation would greatly minimize handling of glass plates and wouldresult in a much lower manufacturing cost. Further, the presentinvention has been illustratively described for gate lines for liquidcrystal display devices; however, the present invention is much broaderand has application to any electroplating process. It is to beunderstood that the present invention is applicable to formingelectroplated metal on any conductive structure including but notlimited to gate lines. For example, data lines, capacitor electrodes,contacts, light shields or other structures for other semiconductordevices may be electroplated in accordance with the present invention.

Now the additional process steps will be described for a four maskprocess sequence for forming a TFT array for a liquid crystal displaydevice. Referring to FIGS. 6A and 6B, a trilayer insulator 20 isdeposited over pixel electrodes 16 and metal layer 18. Tri-layerinsulator 20 may include a layer of silicon nitride 22 followed by alayer of amorphous silicon (a-Si) 24. Tri-layer insulator 20 preferablyincludes a silicon nitride layer 26 patterned over a channel (over gateline 14). Silicon nitride layer 26 may be defined by a combination ofback and front side resist exposures to self align silicon nitride layer26 to gate line 14. Silicon nitride layer 26 is etched to expose theamorphous silicon 24.

Referring to FIGS. 7A and 7B, a highly doped n+ microcrystalline layer28 is deposited over layers 24 and 26. Vias 30 are etched down to pixelelectrodes 16 in the array area and down to gate metal outside the arrayarea. Referring to FIGS. 8A and 8B, data metal 32 is deposited andpatterned to complete the TFT array. Data metal 32 preferably includes aMo/Al/Mo metal layer. Thin film transistors 38 are formed which areenabled by gate 14 to form a channel in layer 24. Contacts (not shown)may be formed directly between the gate metal and data metal through viaopenings formed during via formation as described for FIGS. 7A and 7B.If a data metal etchant attacks gate metal (14 or 18), the gate metal(14 or 18) can advantageously be covered by data metal 32 where there isa via opening in the gate insulator 22.

One significant advantage of electroplating over electroless depositionis that the metal purity (and hence conductivity) is better, additivescan be used to modify the edge profile, and the stress can be lower.Additionally, the current flow can be monitored to determine how muchmetal has been deposited in a given area and this value may be employedin a feed-back loop to control the metal thickness along the lines. Infact, a non-uniform metal thickness along the line could be used ifdesired.

The present invention may be employed in other structures as well, forexample, in a four mask top gate TFT device. Referring to FIGS. 9A and9B, a first step may include deposition and patterning of a light shieldlayer 102 on a substrate 104. Light shield layer 102 may includeCr—Cr_(x)O_(y) cermet or other opaque materials. Substrate 104 mayinclude glass, quartz, a polymer or other transparent material. Lightshield layer 102 is overcoated with an insulator 106, which may includea silicon oxide, a silicon nitride or an organic dielectric.

Referring to FIGS. 10A and 10B, deposition and patterning of a datametal 108, followed by an N+ treatment, is performed. Data metal 108 isetched to form a tapered edge. Referring to FIGS. 11A and 11B, an a-Silayer 110 and a gate insulator 112 are deposited. a-Si layer 110 andgate insulator 112 are patterned by a back exposure and an etch processwhich gives tapered edges.

Referring to FIGS. 12A and 12B, a transparent conducive layer 114 (e.g.,ITO or IZO) is deposited and patterned by lithography or other meanssuch as microcontact printing. A metal layer 116 is electroplated onlayer 114 in accordance with the present invention. Metal layer 114 mayinclude, for example, Ni, Co, Au, Ag, Cu, and/or alloys of these metals.Thin film transistors 36 are formed which are enabled by gate 114 toform a channel in layer 110.

Referring to FIG. 13, a cross-sectional view of an annular nozzle 400 isshown. Annular nozzle 400 is capable of scanning in two directions(e.g., x and y directions). This may be particularly useful forelectroplating between small features or features that are not parallel,such as, for example, wiring between a TFT array and other electronicdevices. Nozzle 400 provides added flexibility to the plating process inaccordance with the invention. In the embodiment shown in FIGS. 13 and14, nozzle 400 includes four flow ducts. FIG. 14 shows a top view ofnozzle 400

Referring now to FIGS. 13 and 14, an inner tube 402 is included forelectrolyte delivery. A first annulus 404 is employed for withdrawal ofthe electrolyte. A second annulus 406 and a third annulus 408 may beemployed for delivery and withdrawal of a rinse solution. Otherconfigurations of electrolyte/solution flow and the number of annuli arealso contemplated. Other embodiments may include a plurality of tubesarranged circumferentially about a center tube or tubes. A plurality oftubes may replace one or more of the annuli. In addition, the inner tubeand the outer flow conduits may include rectangular or other shapedcross-sections. An anode is preferably placed in inner tube 402 orincorporated into the walls of inner tube 402 or forms the walls ofinner tube 402 or other annuli.

Having described preferred embodiments of an electroplating apparatusand four mask TFT array process with electroplated metal (which areintended to be illustrative and not limiting), it is noted thatmodifications and variations can be made by persons skilled in the artin light of the above teachings. It is therefore to be understood thatchanges may be made in the particular embodiments of the inventiondisclosed which are within the scope and spirit of the invention asoutlined by the appended claims. Having thus described the inventionwith the details and particularity required by the patent laws, what isclaimed and desired protected by Letters Patent is set forth in theappended claims.

What is claimed is:
 1. An electroplating apparatus comprising: aplurality of chambers; a first chamber including an anode therein, thefirst chamber including an opening for delivering an electrolyticsolution containing metal ions onto a surface to be electroplated, thesurface to be electroplated being a cathode; a second chamber formedsurrounding the first chamber and having a second opening in proximityof the first opening for removing electrolytic solution containing metalions from the surface to be electroplated; and the plurality of chambersbeing adapted for movement in a first direction along the surface to beelectroplated.
 2. The apparatus as recited in claim 1, wherein theplurality of chambers includes a rinse chamber including a supply ofwater for rinsing the surface.
 3. The apparatus as recited in claim 1,wherein the plurality of chambers includes a pretreatment chamber whichleads the first chamber for pretreating and cleaning the surface to beelectroplated.
 4. The apparatus as recited in claim 1, wherein thesurface to be electroplated includes conductive lines.
 5. The apparatusas recited in claim 4, wherein the conductive lines extendlongitudinally along the first direction.
 6. The apparatus as recited inclaim 4, wherein the conductive lines connect to a common node.
 7. Theapparatus as recited in claim 1, further comprising a plurality of firstchambers and a plurality of second chambers.
 8. The apparatus as recitedin claim 1, wherein the anode includes a consumable metal anode.
 9. Theapparatus as recited in claim 1, wherein the anode includes an inertmetal and the electrolyte solution includes metal ions to be deposited.10. The apparatus as recited in claim 1, wherein the plurality ofchambers includes a suction-drying nozzle, which follows a pretreatmentchamber, for removing a cleaning solution and a pretreatment materialfrom the surface to be electroplated.
 11. An electroplating apparatuscomprsing: a plurality of chambers; a first chamber including an anodetherein, the first chamber including a first opening for delivering anelectrolytic solution containing metal ions onto addressing lines of anactive array of a liquid crystal display device to be electroplated, theaddressing lines being a cathode; a second chamber formed surroundingthe first chamber and having a second opening in proximity of the firstopening for removing electrolytic solution containing metal ions fromthe addressing lines to be electroplated; and the plurality of chambersbeing adapted for movement in a first direction along the addressinglines to be electroplated.
 12. The apparatus as recited in claim 11,wherein the plurality of chambers include a rinse chamber which leadsthe first chamber.
 13. The apparatus as recited in claim 11, wherein theplurality of chambers include a pretreatment chamber which leads thefirst chamber.
 14. The apparatus as recited in claim 11, wherein theplurality of chambers include a suction-drying nozzle, which follows apretreatment chamber or rinse chamber, for removing a rise solution anda pretreatment material from the addressing lines to be electroplated.15. The apparatus as recited in claim 11, wherein the addressing linesinclude one of the materials indium tin oxide or indium zinc oxide. 16.The apparatus as recited in claim 11, wherein the addressing lines areconnected to a common node.
 17. The apparatus as recited in claim 11,wherein the anode includes a consumable metal anode.